Many types of dispensers require a securely sealed cap. This requirement is especially true for vials, particularly laboratory sample vials and dispensers for injectable pharmaceuticals and medicinal agents. The required seal is presently accomplished with a standard snap cap, a crimp aluminum cap, or a threaded cap and a corresponding bottle neck finish.
Many conventional vials have a standard snap cap and neck finish; most aspirin bottles utilize this type of container. In this basic snap cap design, the extended skirt of the cap secures under a protrusion on the neck of the vial such that there is one point of contact between the skirt and vial upon sealing the vial. In addition, those designs which have more than one point of contact do not generally have tight dimensional tolerances between the cap and vial contact points. This type of cap can only be used on vials that have a snap ring for engagement with the skirt of the snap cap.
Another common closure for vials of this type is a crimp cap, which is securely retained on the neck finish of the container by crimping a metallic (usually aluminum) skirt under a lip on the neck of the vial. One advantage of the aluminum crimp cap is that it works on vials having either a standard crimp seal or a snap ring. A disadvantage is that the aluminum crimp cap requires the use of a crimping tool to form a seal. The seal is subject to the amount of squeeze and alignment given by the user. When properly applied, however, the aluminum crimp cap provides a good seal against solvent evaporation.
The crimping tool is made of metal (typically aluminum) to provide the force necessary to deform the aluminum crimp cap and, thereby, either to apply or remove the aluminum crimp cap to or from the vial. Removal of an aluminum crimp cap from a vial is dangerous. If not done properly, the neck finish of the vial can break—leaving ragged glass edges. Moreover, sharp aluminum pieces are exposed as the aluminum crimp cap is literally torn away from the vial.
Still another common closure for vials involves a standard screw thread neck finish on the vial and a corresponding screw thread on the cap. Closure is attained and a seal obtained by twisting or rotating the cap onto the vial. Thus, screw thread closures require finger torque pressure to apply and remove the cap. The seal is subject to the amount of torque applied by the user. When torqued properly, the threaded cap provides a good seal equivalent to or better than the aluminum crimp seal. One drawback is that the threaded cap can lose torque upon relaxation of the plastic material, from which the typical threaded cap is made, which allows the cap to back off the threads. In addition, the threaded cap can only be used on threaded vials.
Improvements to the various caps and closures have been made. The inventor of the present application, James G. Finneran, has patented three such improvements. See U.S. Pat. No. 5,662,230; U.S. Pat. No. 5,772,057; and U.S. Pat. No. 5,857,579—each titled “Crimp Top Seal for Vials.” The improvements generally combine the better properties of the snap cap and the crimp aluminum cap to provide a more safe and secure crimp top seal. These three patents are incorporated into this document by reference.
Regardless of the type of cap used to seal the vial, a need exists to provide easy, quick, and repeatable access to the contents of the sealed vial. This need often means designing the vial assembly to avoid having to remove the cap to access the contents of the vial, a need met by existing devices in a number of ways. One way is taught by U.S. Pat. No. 6,193,064 titled “Cap Closure and Liner” and issued to the inventor of the present application, James G. Finneran. The invention relates to caps for bottles, vials, or other containers and especially to caps for laboratory sample bottles and dispensers containing pharmaceuticals and medicinal agents, which include a penetrable segment for introduction or withdrawal of material from a container on which the cap is mounted. This type of container requires a securely sealed cap which allows quick and easy access to the container contents.
The invention taught in the '064 patent is a cap closure including a top member with a center opening, a dependent skirt, and a liner with a central raised portion which fits into the center opening of the top member. The side walls of the center opening and the liner raised portion are adapted to mate with one another, so that the central raised portion of the liner is retained in the center opening of the top member by an interference fit, thus holding the liner under the top member. The central raised portion may also be concave. The height of the liner raised portion should be no greater than that of the central opening in the cap to minimize contamination and to provide a combination which is relatively easy to assemble but is nevertheless secure from inadvertent mechanical dislodgement of the assembled components.
The liner concept has also been applied in the context of vial trays. Analytical chemistry laboratories use a variety of different sized and shaped vials for different types of experimental assays, including sorbent assays, high-throughput screening assays, and combinatorial chemistry analysis. In those assays, there is a need to provide support for the vials used. Often, the support is necessary to maintain the vials in an upright position to facilitate chemical reactions, prevent assay fluids from escaping from the vials, enable movement of the vials without disturbing the assay, or meet other experimental considerations. Various vial-holding devices, such as microplates or trays, have been used for assays performed in these laboratories, optionally used in autosamplers. Generally, these devices contain multiple compartments for inserting and providing support for vials. U.S. Pat. No. 6,193,064 titled “Multi-Tier Vial Plate” and issued to the inventor of the present application, James G. Finneran, teaches an exemplary vial plate for holding vials.
A component related to the vial tray is a liner as disclosed in U.S. Pat. No. 7,037,580 titled “Pattern Adhesive Sealing Films and Mats for Multi-Well Plates” and issued to the inventor of the present application, James G. Finneran. The disclosed component is a thin (about 2 mils thick) adhesive liner placed over a tray to seal around vials stored in holes (typically 96 of them) in the tray. The adhesive is present on all portions of the liner except in the area of the vials themselves. Therefore, needles can penetrate the liner and enter the vials without contacting adhesive. A vial is disposed under each oval or circular, non-adhesive area on the surface of the liner. Although other materials are suitable, the liner is typically made of polytetrafluoroethylene (PTFE) such as Teflon (a trademark of E.I. du Pont de Nemours & Co., Inc. of Wilmington, Del.). PTFE is “A highly stable thermoplastic tetrafluoroethylene homopolymer composed of at least 20,000 C2F4 monomer units linked into very long unbranched chains.” Merck Index at 7560.
Finally, Whatman plc of the United Kingdom, a leading supplier of separations technology to the life sciences industry, offers noteworthy products on its website (www.whatman.com). Whatman filters are used for research, analysis, and quality control in the pharmaceutical, biotechnology, and environmental testing industries. One particular Whatman product is the UniPrep™ syringeless filter, a preassembled filtration device for the filtration and storage of laboratory samples. This device is quick and easy to use and features a plunger, filter, and vial in one unit. The device replaces syringe-coupled filtration devices with single, disposable units. UniPrep™ devices consist of two parts: a test tube and a filter-plunger. The design incorporates a pre-filter and a membrane into the tip of the plunger. When the filter-plunger is pressed through the liquid placed in the test tube, positive pressure forces the filtrate up into the reservoir of the filter-plunger.
The Whatman Mini-UniPrep™ syringeless filters, with durable plastic caps, provide a faster, easier way to remove particulates from samples being prepared for high performance liquid chromatography (HPLC) analysis. The device allows the user to prepare samples in less than the time required by other methods. The Mini-UniPrep™ is a pre-assembled filtration device consisting of a 0.5 ml capacity chamber and a plunger. The plunger contains a filtration membrane at one end and a pre-attached cap and septum at the other end. The plunger is pressed through the sample in the outer chamber and positive pressure forces the filtrate into the reservoir of the plunger. Air escapes through the vent hole until a locking ring is engaged, providing an air-tight seal. Then the Mini-Uniprep™ device can be placed into any approved autosampler.
To overcome the shortcomings of conventional devices such as those described above, a new seal vial assembly is provided. An object of the present invention is to provide an improved assembly that allows easy, quick, and repeatable access to the contents of the sealed vial. A related object is to provide a vial assembly that avoids having to remove the cap to access the contents of the vial.
Another object is to provide an assembly having two, main, self-aligning components that form a liquid-tight seal. Yet another object of the invention is to provide an assembly with a redundant seal, by which two, separate mechanisms can each individually provide the seal. A related object is to provide a seal that is consistent and minimizes liquid (e.g., solvent) evaporation. It is still another object of the present invention to provide a seal able to assure long-term storage of liquids without leakage. An additional object is to provide a seal vial assembly with dimensional control allowing tolerance variation during use.